J.T. and company scramble to thwart a bioterrorism plot when it's discovered that the plague is being produced in an illegal lab. Meanwhile, J.T.'s relationship with Samantha is tested when she receives an appealing offer.

J.T. is promoted to lieutenant colonel and is put in charge of multiple Special Mission Units across the globe. But his celebration is cut short when terrorists kidnap an admired U.S. general in Spain and kill the man's wife in the process. Meanwhile, Pierce's love life blossoms.